Inner fender removal for weight reduction?

-
66Valiant528

66Valiant528

FABO Gold Member
FABO Gold Member
Joined
Aug 20, 2019
Messages
1,200
Reaction score
951
Location
Medway Ma
So the car needs to go on a diet. More glass parts. Presently the car has J bars from the firewall and connecting bars under the dash to the A pillar bars . Is the
structural integrity of the unibody weekend significantly enough that additional bars need to be added maybe negating the weight loss gained by removing the inner fenders? What happens under the hood now that the inner fenders are gone? This is strictly a drag car. Already have fenderwell headers so the back is open. 66 Valiant. Who has run no inner fenders? My car is presently at 135mph. It was skating earlier at 120 then after some QA1 uppers and a good alignment it goes and stops straight. How does no inner fenders effect the car at speed? Not sure what the pros and cons are . Looking for some experienced feedback.
 
That is what we were thinking remove the rest of the fender wells. Cut weight. One thing led to another and we put a straight axle in it. We didn't like the height so we bought a 6 inch drop axle. Its a lot lighter now. Vega steering box. Bought everything through speedway motors.

100_0051 (2).JPG


100_0029.JPG


100_0032.JPG


100_0033.JPG


100_0034 (2).JPG


100_0035.JPG


100_0036 (2).JPG


100_0037.JPG


100_0038 (2).JPG
 
Current suspension is stock other than QA1 uppers, DA Viking shocks and RMS strut rods. 73 A body spindles. Rear is Calvert split mono DA Vikings S60 Wilwood rear disc.
 
So you cut out sheet metal unibody which adds strength to save weight, then you weld in tubing to get the strength back, which one is heavier?
 
That's my question. Is it worth doing? Who has done it? What are the drawbacks?
 
When you cut the fender wells out, and realize you can hold the whole peice in one hand outstretched, you will conclude it's a waste. The roll bars needed to put the strength back are heavier than what you cut out
 
This is my novice opinion if your car is a dedicated race car already at 135mph then you would need a thought out full cage anyway. So cut out those fenders not for weight savings but for efficiency on wrenching on the motor. Instead of J-bars have the cage extend through the fire wall.

Not sure whose car this is grabbed off the internet but it paints a picture of the room you have and actually with the straight axle you have even more with the removal of the shock tower. Very lean and easy to work. It’s no fun racing with cramped engine compartments.
IMG_5013.jpeg
 
Last edited:
This is mine. I have bars that come from the cage that butt up behind the shock tower and sit on the frame rail. They are welded to the frame rail and the tower. The inner fenders were already cut out of my car when I bought it. Kim

IMG_0304.jpeg


IMG_0303.jpeg


IMG_0302.jpeg


IMG_0305.jpeg


IMG_0306.jpeg


IMG_0363.jpeg


IMG_0364.jpeg
 
You need aprons(inner fenders) or solid structural support(j bars?)to fire wall or better yet to a full cage. Since you compromised the structural integrity of the apron’s with holes for fenderwell headers, the only choice now is obvious. All you are doing to lose weight by compromising structural integrity is actually slowing your car down and to say the least making it dangerous and unsafe. It won’t be long before you fatigue what’s left of your car.

Want to go faster? More horsepower and a reinforced chassis and full cage and more weight.
 
Sorry, 8.5 chassis certified, sub frame connectors motor plate and 8 pt cage plus the J bars.. only thing is J bars are 2 piece. A pillar to firewall plate. Plate to front frame rails. If I cut out the aprons I would make solid bars from A pillars to frame rails.
 
The inner fender on Chrys A bodies is a structural member & acts as a brace/support for the K member....which takes the engine & suspension weight. I would not remove it.
 
I also bought my shell with no front end, just aftermarket front frame rails from the crossmember forward and welded through the floor connectors to the rear. It had stock front suspension. Its pretty dramatic how far the nose drooped when I first lifted the car. As it had no radiator support (or provisions),Stock replacement panels were out. After replacing the cowl and firewall (due to 70's mods)and seeing what's not behind them , don't know why anyone would expect that area to support the front end. I ran my bars to the front side of the-A piller ,the hood springs were a non-issue with the glass nose.
007.jpg
 
We bought the valiant with the cage installed. The problem we ran into was the J bars were to low for the headers to fit. So On the Demon we cut the cowl vent duct out of the body so we can raise the J bar right under the cowl. The valiant is probably going to get the J bars raise by just boring the cowl and a funny car addition to cage. We don't want to get to invasive on the interior and dash. Here is how we cut the cowl on Demon 1. Our Demon 2 will only get the united steel style full weld in frame ties frame ties.

Yes both cars are finally back in the shop. I was going to build the Duster but I believe I have it sold. We'll see? I have more Demon parts then Duster and was made an offer I cannot refuse.

My orange Duster weighed 3650 with full bucket interior loaded with all options including. A mild steel 8 point with swing outs . Spare still fastened in the trunk. fasted recorded time was 10.67 @ 128. So this time like you, We are putting the demon on a diet.

Cowl weighed almost 10 lbs. We even lightened the engine LOL.



100_0022 (2).JPG


100_0024 (2).JPG


100_0028 (2).JPG


100_0109.JPG


100_0026 (4).JPG
 
I've cut all the inner fenders out and replaced it with a roll cage ,front of frame rails to firewall with 4 connecting bars to frame rails ,it makes it a whole lot easier to work on and make front end adjustments , as long as you don't change your mind about wanting to make it a race car
 
The car weighs 3440 with me and 5 gallons of fuel so about #3200 . Most of the weight is 4.5 bore Megablock which weighs 150 more than a 440. Browell bell and an ST1200 Lenco 4 speed . The spool Strange S60 isn't light but not a lot more than my back braced 8.75. I'll send some J bars pics. Swing out drivers bar. Kirky seat. I like the sound of a 7# battery. I presently have a group 31 which probably weighs 35 to 40#.
 
Think of it this way Pro stocks did it. We are doing it out our pro stock demon the cars projected weight with 426 hemi is 2500 dry and 2700 wet
 
I ordered front and rear fiberglass bumpers. I think I'll refrain from cutting out the inner fenders for now. The front bumper with brackets and directionals weighed 33.6 pounds. The new bumpers are 4 pounds each. 66 Valiant.
 
66Valiant528 said:
I ordered front and rear fiberglass bumpers. I think I'll refrain from cutting out the inner fenders for now. The front bumper with brackets and directionals weighed 33.6 pounds. The new bumpers are 4 pounds each. 66 Valiant.
Click to expand...
Good to have the weight on the rear, I never ran fiberglass rear bumpers, only the fronts were acid dipped on the factory Hemi Darts...
 
67/6barracuda said:
This is my novice opinion if your car is a dedicated race car already at 135mph then you would need a thought out full cage anyway. So cut out those fenders not for weight savings but for efficiency on wrenching on the motor. Instead of J-bars have the cage extend through the fire wall.

Not sure whose car this is grabbed off the internet but it paints a picture of the room you have and actually with the straight axle you have even more with the removal of the shock tower. Very lean and easy to work. It’s no fun racing with cramped engine compartments. View attachment 1716316240
Click to expand...
Dam Denis , you shoulda drug me back to look at your ride ! Looks bad *** !
 
Cut it out, I welded the seams after cutting the aprons out.
Most a body race cars I see have it done, I've never heard of anyone saying their car was weakened.
The j-bar will add in plenty of strength and the weight of the bar is still a little lighter than the aprons.
Make sure to tie in your shock towers and it is very strong.
I have a 12 point cage with a couple extra points added in mild steel, plus my 1/8th thick 2×3 framing I only added 260 pounds to the car.
My car should weigh under 3000 pounds with all steel parts.
IMG_20240407_191549486.jpg
 
You must log in or register to reply here.
-

Back
Top